1. Field of the Invention
This invention relates to baby carriages. More particularly, this invention relates to baby carriages designed for use on hard and smooth surfaces, such as interior floors, sidewalks, roads and similar prepared surfaces, as well as on soft or very rough surfaces, such as sand, gravel, stone, bare dirt and grass.
2. Description of Related Art
Baby carriages, baby buggies, strollers, perambulators, pushchairs and the like are well known devices for transporting a baby or small child. Such devices typically have a set of wheels, a frame, a seat or basket for holding the child, and a handle which permits the carriage to be pushed along by the parent.
Heretofore, baby carriages have almost exclusively been designed with relatively hard narrow wheels. Such wheels reduce the contact area with the type of hard surfaces commonly encountered in the home, in buildings or along streets. For such surfaces, the reduced contact area reduces the rolling friction, making it easier for the parent to push the carriage.
Examples of recently issued patents showing baby carriages with narrow wheels for hard surfaces include those seen in U.S. Pat. No. 4,770,437 issued to Glaser on Sep. 13, 1988; U.S. Pat. No. 4,681,340 issued to Pasquini on Jul. 21, 1987 and U.S. Pat. No. 4,632,420 issued to Miyagi on Dec. 30, 1986. Examples of older designs showing this type of construction are seen in U.S. Pat. No. 606,451 issued to English on Jun. 28, 1898 and U.S. Pat. No. 298,784 issued to Seely on May 20, 1884.
Such designs are excellent for use on surfaces that are both hard and smooth, such as the man-made surfaces typically found in buildings and in cities. However, on soft surfaces such as sand, bare dirt, gravel or grass, a hard narrow wheel has a tendency to dig into the surface making the carriage extremely difficult, if not impossible to push.
A further feature shared by most modern baby carriages is one or more swiveling or castering steering wheels, generally located at the front of the baby carriage. Such steering wheels may also be smaller than the other load-bearing wheels. The swiveling action permits the baby carriage to be easily turned from side to side.
However, small wheels are particularly susceptible to the problem of digging in when being pushed across a soft surface. Moreover, the swiveling action creates even greater difficulties on soft surfaces as the steering wheels tend to oscillate from side to side or turn at an angle to the direction of motion as they are being pushed along, greatly increasing friction. This problem is accentuated by the location of the handle at the rear of the carriage which places a greater load on the front wheels as the carriage is pushed, causing the front wheels to repeatedly dig into the soft surface.
Similar problems are encountered on an extremely rough and uneven surface, even if the surface is hard, such as on rough stone, particularly when the front wheels 1) are small, 2) are swivel mounted, and 3) are heavily loaded with the carriage being pushed from a handle located at the rear of the carriage. On such surfaces the small wheels are difficult to push over the hard irregularities of the surface. The swivel mounting of the wheels permits the wheel to swing out of line from the desired direction due to the irregularities, and the location of the handle at the rear magnifies these problems.
As a result, baby carriages and the like have not heretofore been used on soft or rough surfaces. In circumstances requiring a child to be transported over such surfaces, the child is often carried in the parent's arms or in a front sling or backpack device. These solutions, however, suffer from their own drawbacks, principally that the parent must support the weight of the child at all times and is restricted in motion.
Accordingly, one object of the present invention is to provide a baby carriage suitable for use on soft or rough surfaces. Still another object of the present invention is to provide a baby carriage which may be moved by both pushing and by pulling across a soft surface without the necessity of reversing the baby carriage.
An additional object is to provide such a baby carriage which may be easily maneuvered on hard surfaces. Other objects and advantages of the present invention will be readily apparent to one skilled in the art in view of the disclosure which follows.